Penrose, Roger
Society for Industrial and Applied Mathematics, 1987
eBooks
edited by A. Csaszar
North-Holland, 1980
Buku Teks SO
Cambridge University Press, 2005
Buku Referensi
edited by Jean-Marie Henckaerts and Louise Doswald-Beck
Cambridge University Press, 2005
Buku Teks
edited by Michael J. Collins
Academic Press, 1980
Buku Teks SO